An Inland Empire woman may have died from the extreme heat. A postal worker found Cindy Marie Grycel unresponsive lying next to her wheelchair on a stretch of East 40th Street in Riverside. Grycel, who may have been homeless, later died. The coroner's office says the 49-year-old's death appears to be heat related.

For the past five days, temperatures in the Inland Empire have spiked above the century mark, putting those most vulnerable to the heat at risk.

"Particularly for those that are elderly, and I have to stress that, the elderly, sick, homeless, lets reach out to them and make sure that they understand the heat can be a dangerous thing," said Dr. Maxwell Ohikhuare with the San Bernardino County Department of Public Heat.

Meanwhile, California Independent System Operator (ISO) announced that a Flex Alert issued Thursday would continue through Friday but would be dropped for Saturday and Sunday. The Flex Alert means businesses and residents can voluntarily reduce their electricity use during the peak hours of 11 a.m. through 6 p.m. to prevent reserves from falling to emergency levels.

Friday morning, there were about 900 Los Angeles Department of Water and Power customers without electricity in several areas, including Baldwin Hills/Crenshaw, downtown L.A., Fairfax, Lake Balboa, Los Feliz, Mid-Wilshire, Sherman Oaks, Tujunga, West Hills and Westwood.

Also, about 1,500 Southern California Edison customers were reportedly without electricity. Power officials hoped to restore electricity by late morning.

Triple-digit temperatures have many Southlanders cranking up their air conditioning to keep cool as the state continues to simmer under the August heat wave. Utilities are echoing that call for conservation. So far, the state's actual usage is below what California ISO has forecasted, but it is going to be a scorcher this weekend.

"The ISO is not forecasting any blackouts at all, but we are getting into a tight power supply situation because of the heat wave," said Stephanie McCorkle with California ISO.

Southern California Edison advises customers to set thermostats no lower than 78 degrees and to use the fan instead of air conditioning when practical.

Other conservation tips: - Turn off unused appliances - Shut off lights when leaving a room - Close drapes and blinds to keep the sun out - Use appliances during early morning and evening hours - Limit the opening of refrigerators

Southern California Edison also has a program set up called Save Power Days. People can sign up online and receive alerts for especially high usage days. If usage is cut from the previous three days, up to 75 cents a kilowatt is put back on the electric bill.

Friday's temperatures are expected to reach 90s in downtown, 80 for the beaches, 106 in the valleys and as high as 111-116 in the high and low desert areas. An excessive heat warning remains in effect in the Inland Empire, valleys and mountains.

An excessive heat warning means that a prolonged period of hot temperatures is expected. Residents are advised to drink a lot of fluids, stay in cool indoor places and out of the sun, if possible. Authorities also remind people that children and pets should not be left unattended in the sun or in cars with the windows up, even for a short period of time.

In the event you can't avoid being in the sun, health officials say remember to wear sun block, get plenty of shade and keep hydrated. Officials also advise keeping an eye on elderly neighbors and children.

The mercury will easily top 100 degrees in the valleys, where motorists are being advised to take caution with their vehicles, as the high temperatures may cause overheating.

Mechanics at Galpin Ford in North Hills say people need to hydrate their cars just as they hydrate themselves.

Service manager Paul Morris says he's seeing a 25-percent increase in cars coming into their shop due to overheating.

"In the course of a day, you'll just see them towed in. they'll be hose failures, radiator rupture," Morris said.

He emphasized the need for preventative maintenance, which includes checking the fluid levels.

The high temps are drawing crowds to the coast, where lifeguards are ready for a busy weekend.

"We've certainly seen an uptick in beachgoers. Our lifeguards are making more rescues. Boating activity is up and our rescue boats are also making vessel assists and vessel rescues," said Cpt. Gonzalo Medina Long Beach Fire Department's Marine Safety Division.

Medina said he expects even more crowds this weekend.

"We're going to peak-staff our towers. We're going to expect a lot more activity on our water ways," Medina said.